Wheel brakes for vehicles



Feb. 9, 1960 l A. Y. DODGE 2,924,300

WHEEL BRAKES FOR VEHICLES Filed oct. 22, 1954 2 shwrs-snee@b 1` IN V EN TOR.

A. Y. DODGE WHEEL BRAKES FOR VEHICLES Feb. 9, l1960 2 Sheets-Sheet 2 Filed 00'0. 22, 1954 v. v f V F .w

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UnitedStates .heef

j 2,924,300 WHEEL BRAKES Fon VEHICLES Adiel Y. Dodge, Rockford, Ill. Application October 22, 1954, Serial No. 464,121

` s claims. (ci. 18s-70) 'The objects of this invention are to provide a brake moresuitable for high-speed vehicles, a brake more suitable for converting kinetic'energy into heat at high speeds, a brake dissipating. less than one-half the amount of heat energy per square linch of braking area, a brakeprodu'cing more uniform Ydistribution of pressure over the brake line, a brake having increased life of more than twofold for a given diameter, width size.

One of the chief objects of my invention is to provide` a brake 'combining the good qualities and characteristics of bothl an internal shoeV brake and a disc brake-a brake which increases the lining surface more than twofold over that commonly employed per unit of drum diameter.

'A further object of this invention is .to provide a commercially acceptable, completely/,sealed brake, one which does not become wet when-fording a stream.

A further object' is to relieve the seal at high speeds by employing centrifugal force to bring about the release thereof.

'still further object is to provide a brake having a large measure of self-actuation, but of a character more nearly straight-line;y one which'varies more nearly directly proportionally to the change in 'the coeilicient of friction as against a self-actuating brake which varies aceiiicient of friction, and =radians of wrap', or its erql'rivalen't...4

' I attain these objects and others as will be apparent from the following description and drawings, in which: Figure 1V s a fragmentary elevation in section showingparts of a rear axle, wheel hub, wheel, brake drum, a'nd brake;

l Figure 2 is aside elevation of the disc portionof the brake shown in' Figure l;

.Figure 3 is a fragmentary projection viewed from the left-side of Figure 2;

Figure 4 shows an end'elevation of brake shoes in place;

. Figures 5 'and 6 are fragmentary. projections showing side views of Figure 4;

A, Figure 7- is a general cross section of an alternative construction of the brake elements; Y

Figure 8 is a general cross section of another alternative construction;

Figure 9 isa fragmentaryplan view looking down onthe periphery of the brake illustrated in Figure 8;

'Figure'y 10. is also a fragmentary plan view showing a sh'oe return means; v

'Figure ll is a fragmentary section taken on line 1,1-.11 .through Figure 10;

"Figure l2 'shows a fragmentary cross section of the seal employed in Figure 1;

Figure .13 shows a fragmentary detail of the relief valve. shownin Figure 1;'

. Figure 14 rshows a side elevation` of a hydraulic wheel cylinder and automatic adjusting means'ass'ociatedther with...

.. through holes in the disc 32' As will be seen from the foregoing drawings, this brake might be termed a combined internal shoe brake and a disc brake. As shown in thegeneral cross section in Figure 8, each shoe is provided with brake lining on its side face as well as on its peripheral cylindrical surfaces. Ways and means are provided which will be described later to expand the brake circumferentially and at the same time'to spread it axially so that frictional contact is made on the two side faces lying at right angles Vto the, cylindrical surface wherefrictional con-A tact is also made.

In order to provide three braking surfaces for the three lining surfaces to workagainst, my brake drum has a at disc surface at right angles to its internal cylindrical surface. In yaddition thereto, the drum is provided with a cover 20, securely fastened to the drum` and presenting a disc surface parallel to the aforementioned disc surface and spaced therefrom suiciently wide to provide the necessary space for the brake shoe elements.

In the arrangementr shown in Figure 9, fixed abut-. ments 21 are secured to a mounting plate 22, and are* engageable with brake shoes 23 in a manner to prevent angular. rotation thereof about the main axis but .to'

permit radial expansion of the brake shoes 23 to make` contact with the cylindrical surface of the drum and also permit axial movement of the brake shoe members. Opposite to the brake shoes 23 are other brake shoe members 24 connected to the lirst mentioned brake shoe members 23 by means of axiallyy facing cam surfaces- 2,5v and 26 such that any braking force absorbed in brakeshoe members 24 tending to cause'relative rotation of `shoes 23 and 24 cause an axial spreading action.

between thevbrake shoe members 23 and 24, thereby to produce axial side thrusts to create braking action on the disc-surfaces.

brake shoe members 24 are transmitted through the cam members 25 and 26 into the brake shoe members 23, and

eventually delivered to the abutment 21 of brake shoe;

1 In Figure 1, a fragment of rear axle is shown at 27.. Secured thereto is a mounting plate 28 having a peripheralange .on which is loosely supported anarray 'of brake shoes 29 which have cylindrical surfaces 30 overlying the vflange on the mounting plate and disc sur-r faces31 parallel to the cover plate 20. These shoesfl 29 contact disc 32 Athrough cams 33 formed by tapered projections on the disc 32 tting into'complementaryl notches in the cylindrical portion 30 of shoes 29. Disc. 32is anchored at abutment pins 35. Cams 33 and holes i 28 and extending g for abutment 35 carried by the plate to hold it against rotation but to permit axial movement `thereof can be best seen in FiguresV 2 and 3.V

vDisc 32 is provided with brake lining 34. Brake'v shoes; 29 are expanded by a control band 36 explained Y more fully in my Patents 1,994,813 and 2,263,263.Y

The brake members are located within a brake drum 19 having a cover 20 secured' thereto. A fragment of adisc wheel is shown at 37, secured to flange 38 by j drum cover a. form a closed compartment being sealed by seal 40.# Seal 40 is a special seal which willbe described later. Drum 19 is also provided with two relief valves 41,9121' best seen in Figure l3. The purpose ofthe reliefy valvef` 'g is to discharge brake lining dust. and anyV other foreign.; .matter which might find its way into the drum enclosure,

wheel bolts and nuts 39. Drum 19 and "including any' watery which may leak in ina'rlve1"te'ntl'y'.V 'J

2,924,300 .Y Patentedfela.' I9,@1369l All of the braking action, both"l on the cylindrical surfaces and the disc surfaces of the 4.

In operation of this brake-the parts normally Voccupy I in which the arcuateange theposition shrowninV Figure 1 portions 30 of shoes 29 are spaced from the web of the drum and the disc portions 31 and 34` are spaced from thelange offthetlrum` and from the4 cover plate. V

Toiapplythebrake the` operating band 36 isKeXpanded torforceV the shoes 2S'A radially 'outward and engage theange surfaces 30fwithA the web of thedrum.V Frictional drag ofthe drumA onA these ange surfacestendsi toturn the shoes 29 withl thedrum andcauses relativerotation between the shoes 29 and disci 34 which is held` againsty rotation by theabutment pinsl 3S. Through action of` the, cam means 331 the` disc 34 and.` the shoes 29` arel moved axially. away lfrom eachA other to bring rthefdisc` 34 into engagement with the ange of-the drungtiandftov shiftthe disc portions-f31 of" the shoes-29 into-engagement with the, cover plate `20. Thus all of the'friction surfaces are simultaneously eiective to resist rotation ofi thedrum and lthe disc portions ofthe brake'are actuatedl through` the friction drag-exerted onthe anges 30 of: the shoes to produce a highly ecient braking elect witlra` minimum of braking effort.

This brake differs somewhat from the brakes shown in Figures V8 and 9 in that disc 32 and lining 34 replaces the disc portion of` brake 23. i Discv321 is shown in detail inlFiguresZ and 3. Disc 32 audits-lining 34 formv onev continuous disc having recesses to communicatewith three anchor pins 35. v Disc 32 also has six cams33, which areacted upon by the cam surfaces in shoe 29. This construction has certain advantages-over and above thelconstruction shown in Figures 8- and 9'al'tho`ughit islessisymmetrical.

`As a @further modification, I have shown a general section in Figure 7 employing a righthandand left.v

hand. discy734 withsuitable` arcuate-shoes 729 interposed between the-discs. Discs 7341 may be identical todisc 32. as.pr,eviouslyrsh`ownv and are connected 'to the shoes 729J through cams4 33 in `the-same manner. This ar-v rangement provides a symmetrical brakeA in which both thenrighthand-andl left hand discs 734l are anchored at 35iand areprovided with cams 33, to be actuatedby theatangent'ialforce imposed by braking upon sho'es S729.

This arrangement provides-a self-actuation, having nearlyv 50 which may. be'rleather or `a `resilient` composition material held" incontact with'a` sealing surface by garter spring 51, suitablyghoused in:a.housing52 in a usual manner. Y

A special feature'of this seal `lies in thel fctfthat I have placed weighty pellets, 1.53 inside/oftheA garter spring overlapj and vlieL between such that revolution of the assembly will set up centrifugal `force Ain the pellets 53, thereby relieving the load of the garter spring on the sealing member 50.

So that garterspring 51 will nothave a tendency to swirl yaroundj relative to the seal member v50J and thereby .chafe it, I havev provided gussetmembers54;jsecuredf to the inner portion (off the housing 52,'anclarranged` to' r the` coils"4 of "garter spring 151 in a manner v;vhich;` willu permit' garterlspring- 51 toexpand as previouslyl described; prevents."garterspring 51 from".appreciableangular" motion relative to" part 50. v

In this way, If have providedjasealL whlch` wlmove outfof contact the running surfacev at highl speeds, thereby eliminatingwear and friction andheat, although:

the seal is relativelyflarge inftjliameteli` I wish topoint outthat-the seal isunnecessary` athigliA speeds sincethe structure: shown will carry' awaylby centrifugal ,force any; water seeking "entrance into the` closure. Seal 40 fis pressed` into member 20 and turns" therewith, thus;providing'substantially aA nearly continui` ously; revolved* surface exposed `to splash, or' a `sealed joint when'stationary or'moving'slowly. r.

The control members set forth in this disclosure'com-f 1prise an expandingcontrol band36, asmore `fully set.

forthpin r my Patents 1,994,813:1 and 2,263 ,2,631` This conY` trol 'bandi may b e' expanded by a hydraulic.' cylinder such straight-line characteristicsas to selfl actuation .increase 4 caused by increase in the coecient offriction.`

r[This` brake is applied by` expanding shoes- 729,1 into engagementr with the brake drum through an operatingl band 736. Tendency of the shoes to turn with the drum camsrtheldiscsr734 outward into engagement with disc surfaces onthe drum'throughthe cams 33.

vThe arrangement of the shoes 729 of Figure shown in Figure 4 wherein three shoes'arranged in end- `to-end'relationship to form an annular lassemblylis illus- Y trated; As` shown, each., shoe is formed intermediate its] ends-with a= camnotch `33 to `cooperate with complemen tarytucam projections on` the discs 734 and the shoes-are free tomove circumferentially withl the drum in' the, absenceof abutments. Additional'cam; surfaces may be.

providedlatwthe ends of the shoes asillustrated at -33' to `cooperate withl cam projections on` the discs.

. eo The shoes 29V ofFi'gure 1 are similarly shown-` in? Figures v5 and 6. As there i1lustrated,- each shoeis formed intermediate its ends .with alcam notch'33 and is Vtaperedat its ends asillustrated at 33 to provide addi y tionalV carnI surfaces for cooperationrwith cam Yprojections-:on the disc 32. n

In these. various embodiments, I have expansible to the right andto the left axially Y and radi# ally. By expanding the set of cylindrical segmentrnem-f ,bers1.radia.lly,y a braking actionis set up.r Braking action creates-tangential forces. Said `tangential forces are uti-N illustrated a wheel brake which is expansible inthree dire'ctionsv tailed description, seemyPatent'2,596,3180. V i I have shown' an,

as is shown in. Figure 14, 1n which. 60 indicates a more or less 'conventionalwheel cylinderhavingj pistons, to' be expanded by. hydraulic pressure'- Associated'witlithe' cylinder isf'an automaticspacerprovidedwitlione wfay` r escapements. which maybe in the. Iform o f rollers 461"toN1 permitlrodmemher 62' to` moveloutwardly from the cenf` ter, but to .preventtheir returning; 1 Joints 6'4`ar`e provided with lostA motioniconnections 63, connecting them to band. 36.' Webs 65fare shown welded to the controljbandatii` The lost motion, at `63 allowscontrol bands 36 to contract' to provide the necessary radial clearance; for'rnore4 de-t In addition to this actuating means, automatic clearance adjuster in Figure .lf-at 42."` automatic clearance adjuster is'` more fully` described in my yrecently issued PatentfNumber 2,508,105.

Briey, Va` pre-deterrruned amount of clearance exists the shoe i inward "radially" until" clearance 44i`s consumed.' That is, shoulder 45.contacts disc member 46 whicli'i `SeCfllledto the mountingjplate 28by means, not shown. i Friction existsj between split at' 43. Spring 44 pulls v tubes` 47 and disc1 member 48,..v The amount of j'friction Vbeing suflicientgso thatrabouttwiceihe force is required to bring"laboutjmovement` `between 47`andf. 48. as `is the" force exerted by spring 44;` Automatic.fclearancejadf at least one to each shoe member. r ,l ,l

lizedlto expand brake members to the'right andi to then Atthe ends of each-shoe :may beemployed'a return spring, urging the shoes 29and`jcontrolband36 together., ThusA the. contraction ,ofv control .band as [previously 1 d`e` scribed renders a frcetb 'contract shoe`s2,9`.radially also.4

`The parts showninFigures 10.",and1`11.arefajspring 68 overlap the ends of shoes 29 and control band 36, thus to urge them together.

It might be mentioned here that the girling principle works to assist the maintenance of necessary clearance in this brake when equipped as described.

It should be apparent that manual adjusters may be employed instead of automatic lclearance adjusters. While I have shown and described one method of expanding and contracting my brake, it should be apparent that other methods might readily be used such as the means set forth in my Patent 2,590,690.

An inflatable tube might be used instead of my control band 36, very much as was taught by Linderman in his Patent 1,786,438.

Having thus described my invention in two or three embodiments, I wish to point out that an expansible brake, expansible in three dimensions may be arranged in other manners besides those disclosed and that the scope of my invention is limited only by the following claims.

I claim as my invention the following:

1. A brake comprising a rotatable annular drum of channel section opening inwardly, a stationary support adjacent to the drum, a plurality of brake members, means for mounting the brake members on the support within the drum for radial and axial movement relative to each other into engagement with the drum, each of the brake members having a flat Adisc portion and at least one of the brake members having an arcuate shoe portion rigidly connected with the at dise portion, the at disc portions of the brake members being axially opposed and the brake members being movable on the mounting means axially to bring the disc portions into engagement with the anges of the drum respectively and radially to bring the arcuate shoe portion into engagement with the web of the drum, respectively, cam means interconnecting the brake members to urge them axially away from each other to move the disc portions axially into engagement with the ilanges of the drum, abutment means on the support engaging one of the brake members to limit turning thereof relative to the support and operating means to urge another of the brake members radially A outward into engagement with the Web of the drum.

2. A brake comprising a rotatable annular drum of "channel section opening inwardly, a stationary support adjacent to the drum, a pair of brake members, means mounting the brake members on the support within the drum for radial and axial movement into engagement with the drum, each of the brake members having an arcuate flange movable radially on the mounting means to engage the web of the drum and a at disc portion connected to the arcuate ange and movable axially on the mounting means to engage a ilange of the drum, cam means interconnecting the flanges of the brake members to urge the brake members axially apart upon relative rotation thereof, abutment meanson the support engaging one of the brake members to limit rotation thereof relative to the support, and operating means to move both of the brake members radially into engagement with the web of the drum.

3. The brake of claim l in which one of the brake members includes connected flat disc and arcuate shoe portions and the other brake member comprises a at disc portion only and engages the abutment.

References Cited in the le of this patent UNITED STATES PATENTS 1,505,216 Myrick Aug. 19, 1924 1,603,963 Liebowitz Oct. 19, 1926 1,858,973 Steele May 17, 1932 1,906,733 Bendix May 2, 1933 1,930,708 Cunningham Oct. 17, 1933 1,956,315 Collins Apr. 24, 1934 1,989,179 Versluis Jan. 29, 1935 2,020,809 Stock Nov. 12, 1935 2,050,902 Tatter Aug. 1l, 1936 2,057,422 Dickson Oct. 13, 1936 2,065,382 Levy Dec. 22, 1936 2,263,079 Flynn Nov. 18, 1941 2,344,933 Lambert Mar. 21, 1944 2,371,503 Carter Mar. 13, 1945 2,595,860 Lambert et al. May 6, 1952Y 2,602,525 Jurgens July 8, 1952 2,629,473 Vincent Feb. 24, 1953 FOREIGN PATENTS 707,074 Germany June 12, 1941 

